TY - JOUR
T1 - An Isolated Complex of Ethyne and Gold Iodide Characterized by Broadband Rotational Spectroscopy and Ab initio Calculations
AU - Mullaney, John C.
AU - Stephens, Susanna L.
AU - Zaleski, Daniel P.
AU - Sprawling, Matthew J.
AU - Tew, David P.
AU - Walker, Nicholas R.
AU - Legon, Anthony C.
PY - 2015/9/17
Y1 - 2015/9/17
N2 - A molecular complex of C2H2 and AuI has been generated and isolated in the gas phase through laser ablation of a gold surface in the presence of an expanding sample containing small percentages of C2H2 and CF3I in a buffer gas of argon. Rotational, B0, centrifugal distortion, ΔJ and ΔJK, and nuclear quadrupole coupling constants, Ξaa(Au), Ξbb(Au) - Ξcc(Au), Ξaa(I), and Ξbb(I) - Ξcc(I), are measured for three isotopologues of C2H2···AuI through broadband rotational spectroscopy. The complex is C2v and T-shaped with C2H2 coordinating to the gold atom via donation of electrons from the π-orbitals of ethyne. On formation of the complex, the C≡C bond of ethyne extends by 0.032(4) Å relative to r(C≡C) in isolated ethyne when the respective r0 geometries are compared. The geometry of ethyne distorts such that (∗-C-H) (where ∗ indicates the midpoint of the C≡C bond) is 194.7(12)° in the r0 geometry of C2H2···AuI. Ab initio calculations at the CCSD(T)(F12∗)/AVTZ level are consistent with the experimentally determined geometry and further allow calculation of the dissociation energy (De) as 136 kJ mol-1. The Ξaa(Au) and Ξaa(I) nuclear quadrupole coupling constants of AuI and also the Au-I bond length change significantly on formation of the complex consistent with the strong interaction calculated to occur between C2H2 and AuI.
AB - A molecular complex of C2H2 and AuI has been generated and isolated in the gas phase through laser ablation of a gold surface in the presence of an expanding sample containing small percentages of C2H2 and CF3I in a buffer gas of argon. Rotational, B0, centrifugal distortion, ΔJ and ΔJK, and nuclear quadrupole coupling constants, Ξaa(Au), Ξbb(Au) - Ξcc(Au), Ξaa(I), and Ξbb(I) - Ξcc(I), are measured for three isotopologues of C2H2···AuI through broadband rotational spectroscopy. The complex is C2v and T-shaped with C2H2 coordinating to the gold atom via donation of electrons from the π-orbitals of ethyne. On formation of the complex, the C≡C bond of ethyne extends by 0.032(4) Å relative to r(C≡C) in isolated ethyne when the respective r0 geometries are compared. The geometry of ethyne distorts such that (∗-C-H) (where ∗ indicates the midpoint of the C≡C bond) is 194.7(12)° in the r0 geometry of C2H2···AuI. Ab initio calculations at the CCSD(T)(F12∗)/AVTZ level are consistent with the experimentally determined geometry and further allow calculation of the dissociation energy (De) as 136 kJ mol-1. The Ξaa(Au) and Ξaa(I) nuclear quadrupole coupling constants of AuI and also the Au-I bond length change significantly on formation of the complex consistent with the strong interaction calculated to occur between C2H2 and AuI.
UR - http://www.scopus.com/inward/record.url?scp=84941777033&partnerID=8YFLogxK
U2 - 10.1021/acs.jpca.5b06593
DO - 10.1021/acs.jpca.5b06593
M3 - Article (Academic Journal)
C2 - 26305995
AN - SCOPUS:84941777033
SN - 1089-5639
VL - 119
SP - 9636
EP - 9643
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 37
ER -